Assessment of anthropogenic transformation of groundwater recharge conditions in urban areas

A strategic priority for the sustainability of urban areas under climate change is the development of resilient and diversified water supply systems, as the altered urban hydrological cycle disrupts precipitation patterns and the overall water balance. In this context, spring water becomes increasingly valuable, yet the natural recharge of shallow aquifers is threatened by built-up development, changes in soil properties, and the loss of regulating ecosystem services. This study was focused on assessing the degree of anthropogenic transformation of groundwater recharge conditions within the urban areas of Kharkiv, where approximately 30 equipped springs are actively used by the population for drinking purposes. The article examined the extent of anthropogenic alteration of precipitation infiltration conditions in the urban area for three representative springs in Kharkiv (Park Yunist, Oleksiivske, and Hlybokyi Yar), using geospatial analysis. It was found that in typical low-rise residential areas, impervious surfaces constitute up to 29% on average, while in multi-storey residential zones they reach approximately 40% of the total area, owing to the greater space occupied by roads and rooftops. Based on these ratios, it was estimated that impervious surfaces occupy between 17% and 43% of the catchment areas of the studied springs. The findings implied a significant reduction in the natural recharge of aquifers due to the impeded infiltration on impervious surfaces. Direct measurements of the springs’ discharge confirmed that the hydrodynamic regime of the springs is affected not only by the proportion of surface types but also by the technical condition of capture facilities, additional recharge from leaking water supply networks, and the structure of the aquifers. The proposed methodological approach and the results obtained are of high practical importance for local authorities in planning and developing adaptation measures for urban water supply systems in the context of climate change and other environmental challenges and threats